The group agreed that what Fat Neil needed most was to feel like a winner for a change. They would invite Neil that Saturday to a game of Dungeons & Dragons designed by Abed to help Neil reclaim his confidence. At the end of the meeting, they realized that Chang had been there and felt too awkward to mention it. What they couldn't have known was that they had just scheduled the most important game of Dungeons & Dragons ever. A game which not only might save a life, but which would forever change the balance between good and Pierce.

— Narrator

After observing him for several days at school, Jeff notices how depressed his classmate Fat Neil is lately. He feigns an interest in Neil's favorite role playing game, Dungeons & Dragons in order to cheer him up. Jeff realizes he may be suicidal after Neil gives him all his prized gaming materials declaring he won't need them anymore. He enlists the study group's help to play a game of Dungeons & Dragons with Neil to avert a tragedy. Although he is forced to include Chang in this endeavor, Jeff purposefully excludes Pierce, believing him too insensitive to help. However, Pierce learns of their plans believing it to be another group activity he has been excluded from. Jeff convinces Neil to join him and the others for a game in the study room.

All 4 one + Chang minus Pierce.

Neil is suspicious of their motivations despite everyone's reassurances. Abed starts the game acting as Dungeon Master and presents the adventure they will be participating in called, "The Cavern of Draconis". Aware that Neil has his own character he's been playing for years called Duquesne, Abed provides character sheets for the rest specifically tailored for their personalities. Despite the effort he put into creating them, the study group randomly selects a character from the pages he provided. Early in the game, Neil saves the group from a horde of goblins using the Sword of Duquesne, a powerful magical item he acquired over many previous campaigns, and he begins to cheer up.

"HI!!"

Hey, Neil! This is going to be awesome, yo!"

" So we're just going to ignore that hate crime, huh?"

Unfortunately, Pierce chooses that moment to make an appearance, spoiling the good mood. He insists on joining the game but, as he has no character, he has to play as himself with no in-game equipment or even clothes. In an act of chivalry, Neil gives Duquesne's cloak to Pierce to prevent him from dying of exposure. However, Pierce rewards this noble act by stealing his sword through a lucky roll of the die. Chang uses his turn to try and get it back, but Pierce has another lucky die roll which allows him to kill Chang's character. Chang hands in his character sheet and leaves the game, while Pierce taunts Neil by rubbing the sword on his character's genitals. Before the study group can apprehend him, Pierce runs off into the forest, escaping with magical speed granted by Duquesne's cloak.

Pierce makes an unexpected appearance.

Jeff meets with Abed and Pierce outside the room and tries to explain the delicate situation with Neil. Pierce refuses to listen, intent on staying in the game. Since he is working against the group, Abed sends him elsewhere to await his turn. With Neil's reluctant help, the study group decides to search for a pegasus after learning that it's the only thing fast enough to catch up with Pierce. The group enters a village to find information, and Britta's character manages to learn from a gnome waiter that an elf maiden tends a flock of pegasi nearby. Arriving at her place, Jeff tries negotiating with the overtly amorous maiden but becomes uncomfortable role-playing a seduction scene with Abed. Annie takes over and graphically narrates a sexual encounter between her character and the maiden to seal the deal.

The elf maiden is blindfolded but uneasy...

so "Hector" reassures her.

Hector gently cups her left and right...

and the elf maiden reciprocates.

Hector uses four fingers while...

Jeff looks on.

Hector is well-endowed.

The encounter progresses well.

Shirley reacts...

...when Hector gets kinky...

...whileTroy takes notes.

The elf maiden is thoroughly satisfied.

Elsewhere, Pierce bribes Garrett to bring him Dungeons & Dragons books - including a copy of the "The Cavern of Draconis" adventure. After Pierce has his turn in secret, Abed brings him back to the group. The other players use the pegasi to catch up to him and find a body draped in Duquesne's sword and cloak. It is not Pierce, however, but the gnome Britta questioned in the village - Pierce has laid a trap. Using information he found in the adventure book, Pierce located an amulet that grants him control of the dragon Draconis, and he appears on the dragon's back with access to all the dragon's spells. He casts a spell to stop time for the others, then uses a shape changing spell to transform Duquesne to become "as fat as Neil." He then reveals the real reason Jeff is so keen to save Neil: it was Jeff who coined his nickname "Fat Neil".

Pierce waits on his throne.

As everyone absorbs this new information, the group admonishes Jeff while Pierce continues to taunt Neil. Unable to move thanks to the time stop spell, Neil has Duquesne pity Pierce with the rest of the party following suit. Angered, Pierce unfreezes time so he can attack, but this uses up his turn; given a chance to act, Neil throws the Sword of Duquesne at the amulet Pierce is wearing. It is a difficult shot, but the dice roll is high enough, and he succeeds. With the amulet destroyed, Draconis is freed and eats Pierce. He gives his treasure hoard to the players as thanks for his freedom; the group has succeeded in the quest. The group leaves triumphant, and Neil tells Pierce it was the best game of Dungeons & Dragons he's ever played and asks him to play again next week.

Troy and Abed arrive in the study room, arguing about whether it is better to have big ears or a tail, but suddenly realize they are early; another study group made up of older Asian women is currently using the study room. The strangers join in on the discussion.

Although Abed claims to be completely impartial, he allows Pierce to make use of information that is obviously obtained from reading the adventure. This goes against specific rules regarding player knowledge; there are in fact rules in "Dungeons and Dragons" that determine what a character does and doesn't know in the game.

In the original concept, Pierce turns out to be an expert D&D player due to hanging out with Gary Gygax, co-creator of D&D, in the '70s. The concept also had Pierce sealing the others in a cube instead of freezing time, thus causing everyone to start a new game of D&D within the cube (a game within a game) that Pierce could not join as he was outside of the cube.